A Human Factors Analysis and Classification System of Unsafe Acts in Philippine General Aviation Accidents

A Human Factors Analysis and Classification System (HFACS) framework was applied to investigate human error in Philippine General Aviation (GA) accidents from 2019 to 2024. This study focuses specifically on Tier 1: Unsafe Acts, including skill-based errors, decision errors, perceptual errors, routine violations, and exceptional violations. Twenty-six accident reports from the Civil Aviation Authority of the Philippines (CAAP) were analyzed. Frequency distributions, Fisher’s Exact Test, and Cohen’s Kappa for inter-rater reliability were used. Results show Skill-Based Errors as the most recurrent unsafe act, particularly in-flight training and agricultural spraying. No statistically significant association was found between unsafe act type and accident outcome. Trends indicate reduced accident frequency in years with stronger regulatory oversight. The study recommends enhancements in pilot proficiency, regulatory compliance, and HFACS-based safety programs.